---
title: DispatchTimeInterval
framework: dispatch
role: symbol
role_heading: Enumeration
path: dispatch/dispatchtimeinterval
---

# DispatchTimeInterval

A number of seconds, millisconds, microseconds, or nanoseconds.

## Declaration

```swift
enum DispatchTimeInterval
```

## Overview

Overview Use DispatchTimeInterval values to specify the interval at which a DispatchSourceTimer fires or I/O handlers are invoked for a DispatchIO channel, as well as to increment and decrement DispatchTime values.

## Topics

### Enumeration Cases

- [DispatchTimeInterval.seconds(_:)](dispatch/dispatchtimeinterval/seconds(_:).md)
- [DispatchTimeInterval.milliseconds(_:)](dispatch/dispatchtimeinterval/milliseconds(_:).md)
- [DispatchTimeInterval.microseconds(_:)](dispatch/dispatchtimeinterval/microseconds(_:).md)
- [DispatchTimeInterval.nanoseconds(_:)](dispatch/dispatchtimeinterval/nanoseconds(_:).md)
- [DispatchTimeInterval.never](dispatch/dispatchtimeinterval/never.md)

## Relationships

### Conforms To

- [Equatable](swift/equatable.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)

## See Also

### Time Constructs

- [DispatchTime](dispatch/dispatchtime.md)
- [DispatchWallTime](dispatch/dispatchwalltime.md)
- [DispatchTimeoutResult](dispatch/dispatchtimeoutresult.md)
- [dispatch_time_t](dispatch/dispatch_time_t.md)
- [DISPATCH_WALLTIME_NOW](dispatch/dispatch_walltime_now.md)
- [Wall Time Constants](dispatch/2963138-wall-time-constants.md)